Contains lecture ppt of Firearm

1. Firearm Injuries
Dr. Tikendra Dewangan
MD ( Forensic Medicine)
RIMS Raipur

2. What is a firearm?
• A firearm is any weapon which discharges a
missile by the expansive force of the gases
produced by burning of an explosive
substance.

3. What is ballistics ?
a
Ballistics is the science dealing with firearms,
ammunition and the effects from their use.
Proximal
balliastics
Intermediate
balliastics
Terminal
balliastics
Wound
ballastics

4. • Proximal ballistics.
Motion of projectile
Within the firearm
• Intermediate ballistics.
Motion of projectile outside
the firearm
• Terminal ballistics/Wound.
Effect of projectile on target/Body

5. Classification
I. According to the condition of barrel.
II. According to firing action.
III. According to barrel length.
IV. According to muzzle velocity
V. According to Manufacturing process.

6. I. According to the condition of barrel

8. Some Terminology
Barrel:
• The metal tube through which
the bullet is fired
• Steel tube for jetting of the
projectile.
• Two ends --- Breach & Muzzle
Bore:
The inside of the barrel
Smooth bore: Shotguns.
Not smooth bore: rifles,
pistols
Breach end
Muzzle end

9. • Helixometer – device used to measure
internal diameter of barrel or is the
instrument to examine the interior of the
barrel.

10. Rifled Firearm
• Rifling means the inner surface of bore of the weapon from
breech to the muzzle end is thrown into spiral grooves, varying
from 2 to 22 or more (usually 4–7), which run parallel to each
other but are twisted spirally.
• These ‘grooves’ are called ‘rifling’ and the projecting ridges
between these grooves are called ‘lands’.
• Caliber- Ex .22, .30, .32, .45
Caliber

11. What does rifling do to the bullet?
LAND
GROOVE
1. Gives the bullet a spinning or spiraling
motion.
2. A greater power of penetration.
3. A straight course and prevents it from
unsteady movement as it travels in the air.

12. Marking in bullet
1. Primary marking ( Class characteristics) –
a) Due to rifling
b) Each company has different no. of rifling, their
width, depth etc.
c) Indicate making & model of Gun
d) Seen by naked eye
2. Secondary Marking ( Individual characteristics) –
a) Individual variation in each gun
b) Due to repeated wear & tear in each gun
c) Due to Cleaning of gun
d) Seen by Microscope

13. Smoothbore firearm
• No rifling
• Bore- Internal diameter of
shotgun
• Internal diameter of shotgun
expressed by a system k/as –
Gauge
• No. of lead balls, each fitting
the bore, which can be made
from 1 pound (454gm) of
lead

14. • Choking:
It is in the form of small
Constriction at the muzzle
end of shot gun.
Degree of choking is based
upon the percentage of
pellets that will stay inside
a 30 inch circle at 40 yards
• Paradox gun- In some shotgun
rifling is done near muzzle
end.
Smoothbore firearm

15. MLI OF CHOKING
1. 65%- 75% of pellet in
circle- Full choke
2. Increasing the muzzle
velocity of projectile.
3. Maintain shot to remain
together for long distance
4. Enhances the explosive
force

16. – AIR PISTOL:
– Compressed air is used to fire the missile
– In some weapons liquid CO2 is used as propellant
– PEN GUNS :
– used for firing tear gases but can be modified to
fire ordinary cartridge
– ZIP GUNS :
– Home made rifled firearm that is used to fire
single shot.
– STUD GUNS:
– used to fire metal studs into wood, concrete,
steel.

17. CARTRIDGE
• Single Unit of ammunition.

18. CARTRIDGE
• Pellets/shots
• Wad/Card board
• Disc
• Gunpowder
• primer
• Bullet
• Gun powder
• Primer
• Jacket
SHOTGUN RIFLE

19. CARTRIDGE
(SHOT GUN)

20. CARTRIDGE
(Rifle)

21. • Wad- keeps the things apart or in place. Here, it
may be made up of cardboard/ cork/plastic etc

22. CARTRIDGE FIRING SEQUENCE
CARTRIDGE FIRING
SEQUENCE
CARTRIDGE IN CHAMBER
FIRING PIN STRIKES PRIMER OR
CASE RIM AND IGNITES THE
PRIMING COMPOUND
FLAME GENERATED BY
PRIMING COMPOUND IGNITES
POWDER CHARGE
POWDER BURNS RAPIDLY,
GENERATING A VOLUME OF
HOT, HIGH-PRESSURE GAS
GAS PUSHES BULLET THROUGH
BORE AT HIGH SPEED
BULLET EXITS MUZZLE, HOT
GAS MAKES “BANG”

23. Firing

24. Primer (Detonator)
• Most common following
ingredients are used…
 Tetrazene
 Lead Syphnate,
 Antimony Sulphide
 Barium nitrates
BLAST
Percussion Cap:
Primer stored into small
compartment attached to
the base of the cartridge
case. which made up of
copper or zinc

25. RIMFIRE CARTRIDGE
PRIMING COMPOUND IS
CONTAINED IN THE INSIDE OF
THE RIM OF THE CASE HEAD
Primer
RIMFIRE AND CENTER-FIRE CARTRIDGES
CENTERFIRE CARTRIDGE
PRIMING COMPOUND IS CONTAINED
IN A METAL CUP, CALLED A PRIMER, IN
THE CENTER OF THE CASE HEAD

26. Propellant (Gun powder)
This is situated in close proximity to the primer
within the cartridge case.
• Types of gun powder :
1. Black Powder
2. Semi smokeless powder
3. Smokeless

27. Gun Powder
Black powder is a granular mixture of
• potassium nitrate (KNO3) 75%
Which supplies oxygen for the reaction
• Charcoal 15%
Which provides carbon and other fuel for the
reaction
• Sulfur (S) 10%
Which, serving as a fuel, lowers the temperature
required to ignite the mixture, thereby increasing
the rate of combustion

28. Gun Powder
Semi smokeless Powder
• It is a mixture of
80% Black powder
and
20% Smokeless powder
Smokeless powder
• It is contain Nitrocellulose,
Nitroglycerin or
Nitroguanidine
• Three types:
1. Single based:
Nitrocellulose alone
2. Double based
Nitrocellulose &
Nitroglycerin
3. Triple based
Nitrocellulose , Nitroglycerin,
and Nitroguanidine

29. Gun Powder
BLACK POWDER SMOKELESS POWDER
1 Grain on combustion
produce 200-300 cc of
gas.
1 Gram on combustion
produce 3000 – 4500 cc
of gas
More the no of F more fine
the gun powder
Ex- FG, FFG, FFFG
1 Grain on combustion
produce 800-900 cc of gas.
1 Gram on combustion
produce 12000 – 13000 cc
of gas

30. Projectile
• This is usually either a Bullet or a bunch of
pellets(shot).
1. Projectile - Bullet (Rifled Weapons)
2. Projectile - Pellets (Smooth bored
Weapons)

31. Projectile (RifledWeapons)
• A Bullet is a projectile propelled by a firearm,
sling, or air gun.
• Bullets do not normally contain explosives but
damage the intended target by impact and
penetration.
• The word "bullet" is sometimes used to refer to
ammunition generally, or to a cartridge, which is
a combination of the bullet, case/shell, powder,
and primer.

32. TYPES OF BULLET

33. TYPES OF BULLET

34. Projectile (smooth Bore)
Pellets (shot):
• These are spherical projectiles of variables size
used in shotguns.
• No's of pellet or Spheres may varying from 6
to 2600

35. Projectile (smooth Bore) Types
1. BIRD SHOT:
• These are small, 1-3.5 mm in diameter
• It is contain 200-400 shots in a 12 bore shot gun cartridge
• Used for hunting very small animals likes birds
2. Buckshot :
• These are very large shots, 6-8 mm in diameter
• It is contain 9 shots in a 12 bore shot gun cartridge .
• It is made up by moulding so that called mould shot
• Used for big hunting game
3. DUST SHOT :
Very small in size
It is contain 2600 shots in a 12 bore shot gun cartridge

36. Components from a typical
shot shell containing
birdshot and a one-piece
plastic wad.
Components from a typical
shot shell containing
buckshot and a fiber /
plastic wad combination

37. GUNSHOT WOUNDS
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38. Factors responsible for the injurious effects of missile:
Factors inherent to the missile:
1. Speed of the bullet
2. Size and shape of the bullet
3. Character of the missile’s movement in flight
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39. Nature of the target:
1. Density of the target
2. Length of tissue involvement in its course
3. Nature of the media traversed
4. Vitality of the part involved
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Factors responsible for the injurious effects of missile:

40. Components of Cartridge Produce
injury

41. Components of Cartridge Produce injury
Components Specific effects
Gun Flame Heat combustion effect on garments,
Hair singeing
Gun smoke
1. Soot particles
2. Gun powder (Fine)
3. Gun powder (Coarse)
Blackening
Blackening
Tattooing
Cards Minor injuries
Wads Minor injuries
Gases Blow back effect cherry red colour around wound
of entry.
Lead shot /Bullet Wounds of entry
Exit Billiard ball ricochet effect
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42. I. Wound from Shotgun
1. Flame – 15cm to 30cm
2. Smoke – 30cm to 45 cm
3. Unburnt gunpowder – 60m to 90cm
4. Card travel for two metres
5. Wad for 4 – 5 meters

43. Characteristic of wound
 Depends on the distance form which the weapon is
Discharged.
1. Contact & near contact wound
2. Close range ( Up to 1 meter)
a) Up to 30cm ( within the range of smoke)
b) Up to 30cm -1 meter
c) Up to 60 – 90 cm ( within range of gunpowder)
3. Short range ( 1-2 metres) - ( within the range of Card )
4. Intermediate ( 2- 4 metres) –( within the range of Wad)
5. Distance wound ( > 4 meters)
6. Exit wound

45. 1. Contact & near contact wound
• Tight contact discharge over soft tissues
i. Single Large wound with Everted Margins
ii. Shape: irregular
iii. Singeing of hair – present due to escape of flame
in loose contact
iv. Blackening : absent
v. Soiling and burning is minimal
vi. Tattooing: absent in surrounding part but in track
vii. Muzzle impression
viii. Back spatter
ix. Cherry red/Pink tissues from carboxyhaemoglobin
x. Wads in the depth of the wound.

47. Back Spatter

48. 2. Close range
• Upto one metre----Blast effect is less
• Within 30 cm ----skin is singed by flame, Blackened
by smoke, Tattooed by gun powder, Hairs are burnt
• At a distance of 60-90 cm-----single circular 2.5-
4cm diametre, only tatooing seen
• 30cm -1 metre—rat hole

49. 3. Short distance
1. 1-2 metre
2. Size of wound is 4-5cm diameter, irregular
3. No burning, blackening, singeing of hair,
tattooing
4. Wad inside body

51. 4. Intermediate range
1. 2-4 metres
2. Shot mass begin to spread at 2 metres
3. Individual pellet holes detected
4. Wad just strikes the body
5. >3 metres- central aperture with small
openings in 8-10cms

53. 5. Distant range
1. > 4 metres
2. All shot penetrate separately in an area of
10-15 cms
3. Death beyond 30 meters is rare.

55. 6. Exit wounds
• Usually shot gun pellets do not exit except
1. Contact wounds
2. Tangential wounds
3. Thin part of body
4. Wounds of larger calibre buckshot

56. II. Wounds from automatic pistols
1. Flame extends up to 8 cms
2. Smoke extends up to 30 cms
3. Unburnt and burnt powder grains up to 60-
100cms in case of rifles, 40-75cms in case of
handguns

57. 1. Contact wound
2. Close range (shot) – 5 to 8 cm
3. Near shot – up to 50 cm
4. Distant shot – above 50 cm
Characteristic of wound

58. 1. Contact wound:
 Muzzle imprint may be present( absent ; if recoil)
 Large wound with EVERTED MARGINS
 Shape: irregular/ stellate/ cruciate
 Singeing of hair –present due to escape of flame in loose contact
 Blackening/ scorching: absent
 Tattooing: absent in surrounding part but in track
Abrasion collar & dirt collar- present
“Cherry red” discoloration due to CO
A contact shot by pistol –
over top of right shoulder
region:
 cruciate shape due to
cavitation as a result of
blast effect
 “Cherry red”
discoloration due to CO

59. • The abrasion ring, and a very clear muzzle imprint,
are seen in this contact range gunshot wound.
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Muzzle mark
local
burning of
the skin
Cherry red

60. 2. Close range
Entry wound on back of
chest just left to midline
(Level- T5-T6):
Large circular
 Scorching/ blackening-
Present
 Tattooing-Present
1. Within range of flame( 8 cm) – also termed as POINT BLANK
2. Size - Little large( than bullet), circular shape
3. Margins inverted
4. Abrasion ring & dirt ring
5. Blackening/ scorching, singeing of hair PRESENT
6. Tattooing

61. 7/2/2021 61
Tattooing

62. Formation of abrasion collar
&
inversion of margins in case of entry wound

63. 3. Near range
1. Outside range of flame & smoke ; within range of gun
powder i.e upto 50cm
2. Small round hole
3. Smaller than size of bullet
4. Margins inverted
5. Dirt ring - Present
6. Blackening/ scorching, singeing of hair - Absent
7. Tattooing - Present

64. 4. Distant range
 Out side range of flame, Smoke and powder (above
50 cm)
 Entry wound is Smaller than the size of bullet
Circular in shape
 Abrasion collar & Grease collar is present
Singeing of hair
Blackening/ scorching ABSENT
Tattooing

66. Summary of entry wounds
Distance Contact shot
Contact with
skin
Close shot
C− in range of
flame( 8 cm) –
also termed as
POINT BLANK
Near shot
within range
of gun powder
(8-50 cm)
Distant shot
Above 50 cm
Muzzle
imprint
Present Absent Absent Absent
Shape
Large-Cruciate
/stellate
Circular
Size of bullet or
little more
Circular
Smaller than
bullet
Circular
Smaller than
bullet
Margins Everted Inverted Inverted Inverted
Scorching Absent Present Absent Absent
Singeing
of hair
Present Present Absent Absent
Tattooing Present in track Present Present Absent
Abrasion
&
Dirt collar
Present Present Present Absent

67. Entrance vs. Exit Wounds
ENTRY WOUND EXIT WOUND
Smaller than the missile – skin
elasticity except in contact shot
Always bigger than the missile
Edges are inverted, except in
contact shot
Edges are everted
Oval or round No definite shape
“Contusion collar” or “contact
ring” present
“Contusion collar” absent
Tattooing or smudging may be
present
Always absent
Underlying tissues not protruding Underlying tissues may be
protruding
Paraffin test may be positive Paraffin test always negative
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68. A typical entrance wound
A. Single entrance & multiple exit:
i. Entered the body but split into several
fragments, each with separate exits.
ii. Entered body orifice, producing exit.
iii. Two or more bullets have common
entrance, each with separate exit.
iv. Near shot with a shotgun.
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69. B. Multiple wound of entrance & exit
from single shot
• A bullet may pass through an arm and the chest
so that four wounds result. A bullet passing
through the chest or abdomen and thigh and
lower leg, produces six wounds.
• This occurs when the person is running or
sitting in an unusual position.
• When the body surface is irregular, such as the
breast or buttocks, several re-entries and exits
can take place.

70. C. Entrance Wound Is Present But
Bullet Is Not Found In The Body
• This occurs when
(a) the bullet entering the stomach may be
vomited,
(b) entering the windpipe may be coughed up,
(c) entering the mouth may be spit out,
(d) entering the gastrointestinal tract may be
passed out in the faeces
(e) when it is so deviated or turned on coming in
contact with the bone, that it passes out by the
same wound as it entered.

71. D. Entry wound is more than exit:
1. One or more bullets are not through and
through, bullet lodged in the body.
2. All bullets are through and through, one
exited in natural body orifice.
3. Different shots produced different entrances
but 2 or more produced common exit.
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72. Medico legal Importance
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73. 1 .Nature of death due to firearm injury
• Death due to firearm injury may be suicidal,
homicidal or accidental.
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74. Tests for the presence of powder residues:
• On the skin:
– Dermal nitrate test (Paraffin test,
Diphenylamine test, Lung’s test, Gonzales’ test)
• On clothing:
– Walker’s test (C-acid test, H-acid test)
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75. i. Gunshot wound is suicidal:
1. Shot was fired in a closed or locked room.
2. The death weapon is almost always found near the place
where the victim was found.
3. Muzzle of gun in contact with body part.
4. Location of GSW accessible to wounding hand.
5. Shot is always solitary
6. Direction of fire compatible with trajectory of bullet.
7. Personal history.
8. Hand of victim may show gunpowder.
9. Entrance wound do not usually involve clothing.
10. Victim’s fingerprint at butt.
11. May have suicide note.
12. No disturbance in the place of death.
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76. ii. GSW is homicidal:
1. Entrance has no point of election.
2. Fired when victim at some distance from the assailant.
3. Signs of struggle may be present.
4. Disturbance of surroundings may be present.
5. Wounding firearm usually not found at scene of crime.
6. Testimony of witness.
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77. iii. GSW is accidental:
1. Usually one shot.
2. No special area of the body involved.
3. Testimony of assailant, witness.
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78. 2 . The direction of the firing
It is better to try to assess the direction of the firing
from the dispersion of the pellets in cases of
shotgun injuries and from abraded /contused and
grease collars, in case of bullet injuries by rifled
weapons.
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79. • Distance of firing
• The direction of the firing
• 4. Identification of the firearm weapon used

80. Tests for the presence of powder residues:
• On the skin:
– Dermal nitrate test (Paraffin test,
Diphenylamine test, Lung’s test, Gonzales’ test)
• On clothing:
– Walker’s test (C-acid test, H-acid test)
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81. Tests for presence of primer components:
• Harrison and Gilroy Test
• Neutron Activation Analysis (NAA)
• Flameless Atomic Absorption Spectroscopy
(FAAS)
• Use of scanning electron microscope with a
linked x-ray analyzer
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82. Peculiar effects
• Yawning bullet. – Bullet travels in irregular
fashion instead of nose-on.
• Tumbling bullet. – Bullet rotates end on end
during its motion

83. Tandem bullet or piggyback bullet:
• Tandem=One behind other.

84. Ricochet bullet:
• Strikes intervening object.

85. Internal ricochet:
• Rebounds from the inner table of skull.
Souvenir bullet:
• In the body for long time, a dense fibrous
tissue capsule usually surrounds it.

86. • Ricochet Bullet
• Dum Dum Bullet (fragments extensively upon
striking)
• Souvenir Bullet
• Frangible Bullet
• Tandem Bullet / Piggyback / Duplex bullet (one after
another)
• Yawning Bullet
• Tumbling Bullet
• Bullet Embolism
• Concealed Firearm wound
• Test Bullet – Fired in bullet recovery Tank made of
Fresh pork skin, sand bags.
• Crime Bullet / Exhibit Bullet – Bullet found in body.
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87. • Kennedy phenomenon:
Surgical alteration of gunshot wounds makes
evaluation of entrance and exit wound
difficult.
• Rayalaseema phenomenon.
• Shored Exit wound

88. PUPPE’S RULE:
• To determine sequence of shots.
• It states that the fractures from the first injury
develop normally, while those caused by the
subsequent injury are stopped where the
structure of the skull has already been
deployed.